3.1.2. AdvertisementJitter
This is the maximum time (in seconds) by which the
AdvertisementInterval is perturbed for each unsolicited
Advertisement. Note that the purpose of this jitter is to avoid
synchronization of multiple routers on a network, hence choosing a
value of zero is discouraged. This value MUST be an integer no less
than 0 seconds and no greater than AdvertisementInterval.
The AdvertisementJitter MUST be 0.025*AdvertisementInterval .

It should say:

3.1.2. AdvertisementJitter
This is the maximum time (in seconds) by which the
AdvertisementInterval is perturbed for each unsolicited
Advertisement. Note that the purpose of this jitter is to avoid
synchronization of multiple routers on a network.
The value of AdvertisementJitter is not independently configurable;
it is a variable derived internally within the implementation
from the configured value for AdvertisementInterval.
The AdvertisementJitter MUST be set to 0.025*AdvertisementInterval.